Fix comment typos and remove redundant DEV block

packages/react-reconciler/src/ReactFiberBeginWork.js

@@ -1474,33 +1474,19 @@ function updateFunctionComponent(
     context = getMaskedContext(workInProgress, unmaskedContext);
   }
 
-  let nextChildren;
-  let hasId;
   prepareToReadContext(workInProgress, renderLanes);
   if (enableSchedulingProfiler) {
     markComponentRenderStarted(workInProgress);
   }
-  if (__DEV__) {
-    nextChildren = renderWithHooks(
-      current,
-      workInProgress,
-      Component,
-      nextProps,
-      context,
-      renderLanes,
-    );
-    hasId = checkDidRenderIdHook();
-  } else {
-    nextChildren = renderWithHooks(
-      current,
-      workInProgress,
-      Component,
-      nextProps,
-      context,
-      renderLanes,
-    );
-    hasId = checkDidRenderIdHook();
-  }
+  const nextChildren = renderWithHooks(
+    current,
+    workInProgress,
+    Component,
+    nextProps,
+    context,
+    renderLanes,
+  );
+  const hasId = checkDidRenderIdHook();
   if (enableSchedulingProfiler) {
     markComponentRenderStopped();
   }

packages/react-reconciler/src/ReactFiberConcurrentUpdates.js

@@ -249,7 +249,7 @@ function markUpdateLaneFromFiberToRoot(
 }
 
 function getRootForUpdatedFiber(sourceFiber: Fiber): FiberRoot | null {
-  // TODO: We will detect and infinite update loop and throw even if this fiber
+  // TODO: We will detect an infinite update loop and throw even if this fiber
   // has already unmounted. This isn't really necessary but it happens to be the
   // current behavior we've used for several release cycles. Consider not
   // performing this check if the updated fiber already unmounted, since it's

packages/react-reconciler/src/ReactFiberHooks.js

@@ -576,7 +576,7 @@ export function renderWithHooks<Props, SecondArg>(
   //
   // We want memoized functions to run twice, too, so account for this, user
   // functions are double invoked during the *first* invocation of the component
-  // function, and are *not* double invoked during the second incovation:
+  // function, and are *not* double invoked during the second invocation:
   //
   // - First execution of component function: user functions are double invoked
   // - Second execution of component function (in Strict Mode, during